Internal gear pumps are known. They have a ring wheel and a pinion which is arranged eccentrically in the ring wheel and which meshes on a circumferential portion with the ring wheel. The ring wheels are internally toothed gearwheels and the pinions externally toothed gearwheels, and the ring wheel and pinion may also be interpreted as gearwheel of the internal gear pumps. Designation as pinion and as ring wheel serves for distinguishing them. Opposite the circumferential portion on which the gearwheels mesh, there is between the ring wheel and the pinion a sickle-shaped free space which is designated here as a pump space. Arranged in the pump space is a separation piece, against which tooth tips of the two gearwheels come to bear on the outside and inside and which divides the pump space into a suction space and a delivery space. The separation piece, because of its typical shape, is often also designated as a sickle or sickle piece. Another designation of the separation piece is a filling piece. By rotary drive, the gearwheels covey fluid from the suction space into the delivery space. Internal gear pumps without a separation piece, which, to distinguish them, may be designated as annular gear pumps, are also known.
The patent DE 196 13 833 B4 discloses such an internal gear pump with a dedicated housing, by means of which it can be flanged, for example, to an electric motor which serves for driving it. This internal gear pump is not intended for hydraulic vehicle brake systems.
The laid-open publication DE 10 2009 047 626 A1 discloses an internal gear pump for a hydraulic vehicle brake system, which does not have a dedicated housing, but instead is installed in a hydraulic block of a traction control of a hydraulic vehicle brake system. The hydraulic block may be interpreted as a housing of the internal gear pump.
Such hydraulic blocks are known, and they serve for the mechanical fastening and hydraulic connection of hydraulic structural elements of a traction control. Such structural elements are, in addition to internal gear pumps, solenoid valves and hydraulic accumulators for the traction control. The hydraulic block is conventionally a parallelepipedal part made from metal, in particular from aluminum, in which cylindrical countersinks, often of stepped diameter, as receptacles for the hydraulic structural elements of the traction control and bores, which connect hydraulically the receptacles or the structural elements installed in them, are formed.